Large ring gears such as those used in final drives or in transmissions are usually supplied with peripheral external splines which are intended to engage similar splines provided on an internal peripheral surface of the housing within which the ring gear is mounted. Conventionally, retaining rings or tab means are provided on the housing to prevent axial movement of the ring gear: The torque reaction produced by planetating pinions orbiting within the ring gear is carried by the splines provided in the housing.
Ring gears are usually formed from high-strength alloy steel which has been hardened for wear resistance and strength. On the contrary, the housing or gear case is normally manufactured from a softer material such as cast steel. Consequently, the torque load application to the housing splines results in time in wear or deformation of the splines in the housing but not on the splines provided on the ring gear. Such wear or deformation can result in backlash, not only in the immediate connection but in the gear train transmitting power to the ring gear and in some cases in a complete failure of the housing splines.
Inasmuch as final drives and transmission housings are extremely expensive, especially in large earth moving machinery and the like, methods of repair and salvage have been devised for rejuvenating a worn ring gear-housing assembly. One method which has been used involves the building up of worn housing spline teeth by means of welding followed by remachining of such spline teeth on the ring gear and the housing to provide proper mating. This procedure involves considerable time and expense and requires large and specialized machine tools.
It is an object of this invention to provide a new ring gear-housing combination wherein the ring gear is retained within the housing by inexpensive, easily replaceable means.
It is a further object of this invention to provide means for salvaging a conventional splined interface ring gear-housing assembly or combination.
Still another object of this invention is to provide a method whereby the novel ring gear-housing assembly presented herein may be salvaged for further use after sufficient wear has occured to render it inoperative.
Other objects and advantages of the invention will become apparent from the following description and claims.